Digital Commons Network^™

Mercury In Big Cypress Bayou And Caddo Lake Watersheds In Marion And Harrison Counties Texas, Joseph Watkins

Electronic Theses and Dissertations

Caddo Lake has been included on the Texas Commission on Environmental Quality 303(d) list for impairment due to mercury (Hg) content since 1996. One of the primary tributaries, Big Cypress Bayou, flows across Eocene-aged rocks and sediments associated with the Wilcox Group; the Wilcox is of interest because it contains lignite coal, which has a direct link to mercury. Previous research has focused on dry deposition from fossil fuel combustion as the primary source of mercury but has not addressed the potential watershed contribution to mercury concentrations in Caddo Lake.

Big Cypress Bayou flows through Harrison and Marion counties in …

Petrography And Petrology Of The Yürekli (Balıkesir) Volcanics: An Example Of Post-Collisional Felsic Volcanism In The Biga Peninsula (Nw Turkey), Ece Simay Saatci, Zafer Aslan

Bulletin of the Mineral Research and Exploration

In this study, the aim was to determine the petrography, geochemistry and source of the Yürekli volcanics (Biga Peninsula, NW Turkey). Tertiary volcanism is widespread in Western Anatolia (NW Turkey), which is an important area where tectonic and magmatic events are observed together. Yürekli volcanic rocks comprise dacitic lavas and pyroclastics. Dacitic lavas show porphyric and hyaloporphyric texture, and consist of plagioclase, quartz, amphibole, biotite, sanidine and Fe-Ti oxide minerals with apatite and zircon accessory minerals. Petrologically, they have high-potassic and calc-alkaline characteristics. Yürekli volcanics show enrichment in large ion lithophile elements (LILE) and are depleted in high field strength …

Geochemical Characteristics Of Gabbroic Rocks In Zyarat In North East Of Iran, Ghassem Azi̇zzadeh, Mostafa Raghi̇mi̇, Seyed Jamal Shei̇khzakari̇aee, Aziz Rahi̇mi̇ Chakdel

Bulletin of the Mineral Research and Exploration

The mafic rocks outcrops exposed in the South of Gorgan, northeastern of Iran. These gabbroic rocks are intruded into the Middle–Upper Paleozoic sedimentary rocks and Gorgan schist units representing a part of the north Gondwana province. Petrography studies of these rocks show medium to coarse grained sizes and the texture varies from ophitic to intergranular under polarized microscope. The mineralogical composition of mafic dykes is dominated by large crystals of clinopyroxene + orthopyroxene + plagioclase and hornblende. These rocks can be classified as gabbroic rock. Geochemical studies show that these rocks have low to medium K₂O contents. The …

Mineral Chemistry, Whole-Rock Geochemistry And Petrology Of Eocene I-Type Shoshonitic Plutons In The Gölköy Area (Ordu, Ne Turkey), İrfan Temi̇zel, Emel Abdi̇oğlu Yazar, Mehmet Arslan, Abdullah Kaygusuz, Zafer Aslan

Bulletin of the Mineral Research and Exploration

The Eocene intermediate to felsic plutons are widespread in varying sizes and compositions throughout the Eastern Pontides Orogenic Belt in NE Turkey. Of these, two monzonitic bodies (namely the Eriko Tepe and Göl Tepe Plutons) in the Gölköy (Ordu) area, extend nearly in the orientation of NW-SE and E-W and were emplaced into the Upper Cretaceous and/or Eocene volcanic and sedimentary rocks. Petrographically, the studied monzonitic plutons are compositionally fine to medium grained monzonite, monzodiorite and subordinate quartz-monzonite. They consist of plagioclase (An_35-67), K-feldspar (Or_61-96), quartz, clinopyroxene (Wo_28-49En_35-51Fs_10-25), biotite (Mg#: …

Holocene-Pleistocene Climate Variability Through Stalagmites, Sevag Mehterian

Open Access Dissertations

Understanding the changing climate of the past is the key to understanding the changing climate of the present. Historically, various geologic mediums have been used to unearth the mysteries of the ancient past. These include cores of sediment from deep within the oceans, ice cores from glaciers, skeletons of coral reefs, and stalagmites from inside caves. This dissertation aims to shed light on the climate of the past 300,000 years as recorded within the geochemistry of stalagmites from caves in the Bahamas and Iran. With oxygen and carbon stable isotope geochemistry, radiometric dating through Uranium and Thorium, and trace elemental …

U–Pb-Dated Flowstones Restrict South African Early Hominin Record To Dry Climate Phases, Robyn Pickering, Andy I.R. Herries, Jon D. Woodhead

KIP Articles

The Cradle of Humankind (Cradle) in South Africa preserves a rich collection of fossil hominins representing Australopithecus, Paranthropus and Homo1. The ages of these fossils are contentious2,3,4 and have compromised the degree to which the South African hominin record can be used to test hypotheses of human evolution. However, uranium–lead (U–Pb) analyses of horizontally bedded layers of calcium carbonate (flowstone) provide a potential opportunity to obtain a robust chronology5. Flowstones are ubiquitous cave features and provide a palaeoclimatic context, because they grow only during phases of increased effective precipitation6,7, ideally in closed caves. Here we show that flowstones from eight …

P-T-X Constraints On Ilmenite Unit Cell And Relationship To Kimberlitic And Non-Kimberlitic Sources, Mitchell R. Galarneau

Electronic Thesis and Dissertation Repository

This research investigates the mineral ilmenite, focusing on the relationship between crystal structure and geochemical and/or pressure data. Ilmenites were obtained from diamond-rich and diamond-poor kimberlites and non-kimberlitic localities, to discriminate between these populations. Crystallographic results showed a delineation between kimberlitic and non-kimberlitic ilmenites at a c-axis value of 14.02 (±0.01) Å. Adding geochemistry and pressure enhances the separation of kimberlitic and non-kimberlitic samples; however, this isn’t the case for diamond-rich versus diamond-poor kimberlites, even with three-dimensional and cluster analyses. A subset of kimberlitic ilmenites (manganese rich) were found with c-axis values and geochemical concentrations similar to non-kimberlitic ilmenites.

By …

Unroofing History Of The Northwestern Ethiopian Plateau: Insights From Low-Temperature Apatite Thermochronology, Shelby Bowden

Masters Theses & Specialist Projects

The geology of Ethiopia is dominated by the Ethiopian Plateau that is similar in elevation to, but aerially larger than, the Colorado Plateau. Several rivers have incised through the plateau, creating gorges that reach up to 1.5 km in depth. The plateau uplifted to its current elevation and was subsequently incised sometime after the Oligocene flood basalt event that signaled the arrival of the African Superplume below Kenya and Ethiopia. Due to its size and extent, published climate modeling has indicated that Late Cenozoic plateau formation could have been a driving force in the East African Cenozoic climate changes. Although …

A Targeted Investigation Of The Upper Contact Unit Of The Sudbury Igneous Complex In The North Range, Sudbury Impact Structure, Canada, Lindsay E. Debono

Electronic Thesis and Dissertation Repository

The Sudbury Igneous Complex (SIC) represents the remnant of a crystalline impact melt sheet of the Sudbury impact structure; and is historically and presently a strategic exploration target sustaining the region's prolific mining camp. In order to better understand the SIC, it is critical to investigate the chilled upper contact of the SIC, which has historically received little recognition. Through field observations, whole rock geochemistry, petrography, and electron microprobe analysis, this study concludes that the SIC upper contact is in fact extensive across the North Range of the SIC. Additionally, the geochemistry of the SIC units, offset dykes, and upper …

Replacement Times Of A Spectrum Of Elements In The North Atlantic Based On Thorium Supply, Christopher T. Hayes, Robert F. Anderson, Hai Cheng, Tim M. Conway, R. L. Edwards, Martin Q. Fleisher, Peng Ho, Kuo-Fang Huang, Seth G. John, William M. Landing

School of Geosciences Faculty and Staff Publications

The measurable supply of ²³²Th to the ocean can be used to derive the supply of other elements, which is more difficult to quantify directly. The measured inventory of an element divided by the derived supply yields a replacement time estimate, which in special circumstances is related to a residence time. As a proof of concept, Th‐based supply rates imply a range in the replacement times of the rare earth elements in the North Atlantic that is consistent with the chemical reactivity of rare earth elements related to their ionic charge density. Similar estimates of replacement times for the …

Applications Of Mineral Chemistry To Petrogenesis And Exploration In Conduit-Type Cu-Pge Deposits, Matthew Jacek Brzozowski

Electronic Theses and Dissertations

The mineralogy and mineral chemistry of Fe-Ti oxides, sulfides, and vein-hosted silicates has been used to characterize the petrogenesis of the Eastern Gabbro of the Coldwell Complex, Ontario, to better characterize the processes that generated and modified copper and platinum-group element (PGE) mineralization that it contains, and to develop and test exploration tools in this system. Understanding these processes is critical to an understanding of conduit-type Cu-PGE systems and their exploration potential. Fe-Ti oxides in the Eastern Gabbro exhibit a continuum of mineralogically distinct exsolution textures. Trellis-type intergrowths, which have systematically higher Fe3+ : Fe2+ and multivalent-element concentrations than cloth-type …

Examination Of Technetium Transport Through Soils Under Contrasting Redox Conditions, Rebecca Solt Dozier

All Theses

Understanding the behaviors of technetium (Tc) during sorption to and desorption from soils amended with titanomagnetite nanoparticles and in redox transition zones is critical for understanding risks from technetium-99 (99Tc) releases into the environment. In this work, experiments were performed under variable redox conditions to evaluate the sorption and desorption behavior of 99Tc in the presence of soil from the Savannah River Site (SRS) and varying concentrations (0.01, 0.1, 1, 10 wt%) of titanomagnetite (Fe3-xTixO4) nanoparticles. Kinetic batch experiments were conducted to investigate how reducing and variable redox conditions and titanomagnetite nanoparticles affect the reduction (sorption) and re-oxidation (desorption) kinetics. …

Controls On Deuterium Excess Across Asia, John Bershaw

Geology Faculty Publications and Presentations

Deuterium excess (d-excess) is a second-order stable isotope parameter measured in meteoric water to understand both the source of precipitation and the evolution of moisture during transport. However, the interpretation of d-excess patterns in precipitation is often ambiguous, as changes in moisture source and processes during vapor transport both affect d-excess in non-unique ways. This is particularly true in Asia where continental moisture travels a long distance across diverse environments from unique moisture sources before falling as precipitation. Here, I analyzed published d-excess records from meteoric water throughout Asia to better characterize what influences d-excess values. I conclude that, (1) …

Mineralogical Findings From Manganese Deposits In The Artova Ophiolite Complex, Derbent-Eymir Area, Yozgat, Turkey, Nursel Oksuz

Bulletin of the Mineral Research and Exploration

The Artova Ophiolitic Complex (AOC), which formed in association with Alpine Ophiolites, is exposed in the NE part of central Anatolia, in the interior of the central Black Sea region and within the borders of Çorum and Yozgat. The Derbent-Eymir manganese- oxide deposit under investigation occurs within this ophiolitic complex. The mineral association in Derbent ore is composed chiefly of pyrolusite, manganite and lesser amounts of ramsdellite, magnetite and goethite. Calcite is the main gangue mineral. The mineral association in Eymir ore is represented by pyrolusite, braunite, neltnerite, jacobsite, psilomelane and trace amount of limonite accompanied by some gangue minerals …

Geochemistry Of Surface Waters And Groundwater At Eku’S Meadowbrook Farm, Madison County, Kentucky, Reid E. Buskirk

Honors Theses

Agricultural activities often contaminate watersheds with excess nutrients leading to poor water quality and eutrophication. Eastern Kentucky University (EKU) Meadowbrook Farm raises crops and livestock, which contribute dissolved nutrients to the neighboring Muddy Creek watershed. Our goal is to understand Farm water geochemistry to develop methods to sequester phosphorous and limit nutrient contamination.

During the Cindy storm event, concentration of Ca²⁺, Mg²⁺, and Na⁺ within baseline source waters decreased with increasing discharge through the weir. This behavior represents dilution of Farm groundwater by storm precipitation. However, K⁺ spiked concurrently with increased discharge then progressively …

Spatiotemporal Variation Of Land-Use And Land-Cover In The Nairobi River Watershed, And Its Effects On The Inorganic Geochemistry Of Nairobi River, Francis Muchemi

Geosciences Theses

Determining the effects of LULC and development on natural resources is necessary for sustainability. This study focused on LULC changes in NRW over the past 3 decades and the effects it had on the geochemistry of NR channel’s sediment. Impervious surfaces increased from 2.5% to 11.9%. Samples from the urban class had elevated levels of contaminants than other classes. The concentrations of major inorganic elements were normal compared to the juvenile UCC except MnO and P₂O₅ that were heterogeneously distributed and significantly enriched. Heavy metals exhibited high DR than USEPA SSL in urban. Pb, Ce and Sb …

Tracking Sulfur Diagenesis In Methane Rich Marine Sediments On The Cascadia Margin: Comparing Sulfur Isotopes Of Bulk Sediment And Chromium Reducible Sulfur, Sarah Chaviva Turner

Master's Theses and Capstones

Methane gas is produced in anoxic marine sediments by methanogenic bacteria and can be ephemerally stored in gas hydrate deposits, escape to the seafloor at methane seeps, and/or be consumed at depth by the anaerobic oxidation of methane (AOM). One way to examine changes in methane flux in cold seep environments through time is to identify past positions of the sulfate methane transition zone (SMTZ) where AOM results in sulfate and methane consumption and bicarbonate and hydrogen sulfide production, often resulting in the precipitation of authigenic carbonates and iron sulfides. One method to identify paleo-positons of the SMTZ is through …

Ecosystems, Communities, And Species: Understanding Mammalian Response To Ancient Carbon Cycle Perturbations, Abigail Carroll

Doctoral Dissertations

Abrupt perturbations of the global carbon cycle during the early Eocene are associated with rapid global warming events. Recent studies have observed mammal dwarfing during the most severe of these ancient global warming events (or “hyperthermals”), known as the Paleocene-Eocene Thermal Maximum (PETM, ~56 mya). Chapter I of this dissertation establishes a stratigraphic framework around two subsequent and smaller-magnitude warming events known as ETM2 and H2 (~53.7 mya and ~53.6 mya, respectively), which have recently been documented in the strata of the Bighorn Basin of Wyoming. Such a stratigraphic framework is crucial for placing fossil localities into stratigraphic context, which …

Characterizing The Geochemical Changes Across A Strain Gradient In The Beja-Acebuches Metabasites Due To Retrograde Metamorphism And Fluid Flow Along The Southern Iberian Shear Zone, Sheryl Stephenson

Theses and Dissertations

The Southern Iberian Shear Zone (SISZ), SW Spain, provides an ideal location to study the effects of syntectonic fluid on rock chemistry, deformation, and metamorphism. The SISZ is a 60km long, 300-500m wide shear zone, striking 115 and dipping approximately 50 degrees to the NNE, that follows the contact between metamorphosed MORB-derived Acebuches metabasites (AB) of the Ossa-Morena zone and the metamorphosed Pulo do Lobo (PdL) accretionary prism. Both units underwent two deformational events: 1) a HT/LP event that reached amphibolite facies and significantly dehydrated the rocks, and 2) a retrograde metamorphic event from amphibolite-greenschist facies that required the addition …

Chemical And Statistical Analysis Of Karst Groundwater Basin Signatures - Springfield, Mo, Benjamin E. Lockwood

MSU Graduate Theses

Springfield, MO is located on the Springfield Plateau physiographic province. The Springfield plateau contains a number of Mississippian aged units and is mainly capped by the Burlington-Keokuk Formation. The Burlington-Keokuk is a highly fossiliferous limestone with nodular and interbedded chert. Beneath the Burlington-Keokuk lies the Elsey, Reeds Spring, and Pierson Formations respectively which comprise the Springfield Plateau aquifer hydrostratigraphic unit. Within the Springfield Plateau aquifer, a well-developed karst system includes springs, sinkholes, and caves. The Springfield Plateau aquifer is the predominant source for springs and seeps in the Springfield area. The purpose of this study was to understand the differences …

Hydrothermal Alteration At Devil's Kitchen In The Lassen Volcanic National Park: A Mars Analogue, Andy Wanta

Theses and Dissertations

The Devil’s Kitchen hydrothermal site, within the Lassen Volcanic National Park, has hydrothermal features that cover a wide range of pH conditions (2-7). Analysis of mineral precipitates, hot spring mud, unaltered substrate rock, and hot spring and meteoric water reveal a wide variety of alteration minerals, geochemical conditions, and water chemistry. Mineral suites included primary igneous phases, silica phases, clay minerals, and sulfate phases. Aluminum sulfates are the dominant sulfate species present with abundant Na+, Fe3+, and Ca2+ sulfate phases and less common K+ sulfates. Amorphous silica precipitates were observed in three samples from a near-neutral hot spring and one …

Understanding The Late Mesoproterozoic Earth System From The Oldest Strata In Grand Canyon: C-Isotope Stratigraphy And Facies Analysis Of The 1254 Ma Bass Formation, Grand Canyon Supergroup, Az., Usa, Erin C. Lathrop

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rocks provide insight into ancient times before complex animals existed. The oldest sedimentary rocks in Grand Canyon (the Bass Formation) allow us to glimpse into what things might have been like over a billion years ago. These rocks record the time known as the Mesoproterozoic Era (1.6 to 1.0 billion years ago), otherwise known as the ‘boring billion’. These rocks are thought to be the right age to indicate the end of an oddly stable world when continents were quiet and life was calm, yet they predate younger rocks that record extreme events. The Bass Formation, some of the only …

Late Quaternary East African Environmental Change Based On Mineralogical And Geochemical Analysis Of Outcrop And Core Material From The Southern Kenya Rift, Nathan Rabideaux

Chemistry Dissertations

The Olorgesailie Drilling Project (ODP) and Hominin Sites and Paleolakes Drilling Project (HSPDP) targeted sites in the East African Rift Valley for their archeological and geological significance. The ODP team collected cores from the Koora Graben and the HSPDP team from Lake Magadi. To compliment these projects, we collected samples throughout southern Kenya to identify weathering patterns and potential mineral reactions to trace geologic processes between geologic sources and the hydrologic sump of Lake Magadi.

Mineralogical and geochemical analyses of the ODP and HSPDP cores suggest a similar paleoclimatic history over the past ~1.0 Myr: long-term aridification and intensifying climate …

An Investigation Of Hydrothermal Veins Along The Foy Offset Dyke, Sudbury Impact Structure, Ontario, Sarah Ann Codyre

Electronic Thesis and Dissertation Repository

A multi-stage hydrothermal system is related to the 1.85 Ga Sudbury impact structure. This system began in the Sudbury Igneous Complex (SIC) and radiated outward along the offset dykes. Through the combination of orientation measurements of veins in the field, petrography and geochemistry of these veins, this study has determined that there are four types of hydrothermal epidote-quartz veins categorized by their orientation, petrography and geochemistry. This study discovered that there are general trends with increasing distance from the SIC along the Foy Offset Dyke. From this it can be concluded that this is in fact SIC-driven hydrothermal event not …

Source, Transport, And Age Of Sediment From Cascade Volcano Watersheds To The Nearshore: Insights For Contaminant And Ecological Studies, Renee Takesue, Kathy Conn, Margaret Dutch

Salish Sea Ecosystem Conference

Inputs of sediment and sediment-bound contaminants from urbanized watersheds to the nearshore region are a growing concern as coastal populations increase around the Salish Sea and worldwide. Geochemical sourcing and aging of nearshore sediment is one potential way to: a) distinguish land-derived sediment in nearshore environments, b) gain insights about how sediment and contaminants are redistributed, and c) determine how recently they were deposited. Sediments from Cascade volcanoes have distinct geochemical compositions that allow discrimination between land-derived (volcanic) and marine (lowland) sediment. As sediment is transported by rivers to the nearshore, it adsorbs particle-reactive contaminants and short-lived radionuclides, and the …

Mineralogy And Sulfur Isotope Geochemistry Of The Apex And Bonanza Prospects At The Golden Sunlight Mine, Montana, Hamadou Gnanou

Graduate Theses & Non-Theses

The Golden Sunlight mine, located 50 km to the east of the famous Butte porphyry/lode deposits, is the largest gold mine in Montana, and has produced over 3 million ounces of gold in its 35+ year history. Most of this gold has come from the Mineral Hill breccia pipe (MHBP), a west dipping, cylindrical body of brecciated latite and country rock fragments of the Precambrian LaHood and Greyson Formations. The breccia pipe is late Cretaceous in age (84±18 Ma, DeWitt et al., 1986), is silicified, pyrite-rich, and is mineralized with gold, silver, and minor base metals. Because the MHBP has …

Carbon Flux And Weathering Processes In Icelandic Glacial-Fed Rivers, Allison Quiroga

Masters Theses & Specialist Projects

An investigation into the carbon dynamics and weathering processes occurring in Icelandic glacial-fed streams was conducted during the spring to summer seasonal transition in June of 2017. Four major outlet rives were sampled from the glaciers of Gígjökull, Steinsholtsjökull, Sólheimajökull, and Falljökull. Markarfljót, the major river that Gígjökull, Steinsholtsjökull, and many other glaciers drain into, was also sampled. Longitudinal sampling occurred at all sites to capture downstream trends in the hydrogeochemistry and carbon dynamics. Distinct differences in geochemistry between glacier surface meltwater, sub-glacial waters, pro-glacial lake water, and post-mixed downstream samples were evident in the data. Glacier surface streams were …

Geochemistry And Mineralogy Of Late Quaternary Loess In The Upper Mississippi River Valley, Usa: Provenance And Correlation With Laurentide Ice Sheet History, Daniel R. Muhs, E. Arthur Bettis Iii, Gary L. Skipp

United States Geological Survey: Staff Publications

The midcontinent of North America contains some of the thickest and most extensive last-glacial loess deposits in the world, known as Peoria Loess. Peoria Loess of the upper Mississippi River valley region is thought to have had temporally varying glaciogenic sources resulting from inputs of sediment to the Mississippi River from different lobes of the Laurentide Ice Sheet. Here, we explore a new method of determining loess provenance using K/Rb and K/Ba values (in K-feldspars and micas) in loess from a number of different regions in North America. Results indicate that K/Rb and K/Ba values can distinguish loess originating from …

Identifying The Origins Of Volcanic Ash Deposits Using Their Chemical And Physical Compositions, Emmanuel Soto

FIU Electronic Theses and Dissertations

Recent ocean sediments collected offshore Chile by Ocean Drilling Program Leg 202 contained layers of volcanic ash of unknown origin. These deposits may have originated from sources in the Southern Volcanic Zone (SVZ) within the Andean Volcanic Belt to the east, or from explosive volcanoes in the southwestern Pacific transported by westerly prevailing winds. In this study, mineral and glass textures and compositions of Leg 202 ashes were evaluated to try to determine the sources of the ash layers. Ash fragments were imaged and analyzed for major elements using an SEM with X-Ray detector and for trace elements using LA-ICPMS. …

Characterization Of Groundwater And Surface Water Geochemistry In An Agricultural Setting At Eku Meadowbrook Farm, Madison County, Kentucky, Reid E. Buskirk, Walter S. Borowski, Jonathan M. Malzone

EKU Faculty and Staff Scholarship

Agricultural activities often contaminate watersheds with excess nutrients leading to poor water quality and eutrophication. Eastern Kentucky University (EKU) Meadowbrook Farm raises crops and livestock, which contribute dissolved nutrients to the neighboring Muddy Creek watershed. Consequently, the Farm is developing methods to sequester phosphorous and limit nutrient contamination.

Before phosphorous sequestration methods can be tested, Farm surface water and groundwater geochemistry must be better understood to determine hydrological pathways for nutrients. We use naturally-occurring dissolved cations, pH, oxidation-reduction potential (ORP), specific conductivity (SC), dissolved oxygen (DO%), total hardness, and alkalinity as chemical tracers to parse the contribution of dissolved ions …